PET of HER2-positive pulmonary metastases with ¹⁸f-ZHER2:342 affibody in a murine model of breast cancer: comparison with ¹⁸f-FDG
Journal of Nuclear Medicine, 53(6), 939–946
Abstract
UNLABELLED: Targeted therapies often depend on the expression of the target present in the tumor. This expression can be difficult to ascertain in widespread metastases. (18)F-FDG PET/CT, although sensitive, is nonspecific for particular tumor markers. Here, we compare the use of a human epidermal growth factor receptor 2 (HER2)-specific (18)F-Z(HER2)(:342)-Affibody and (18)F-FDG in HER2-expressing pulmonary metastases in a murine model of breast cancer.
METHODS: The lung metastasis model was established by intravenous injection of MDA-MB-231(HER2)-Luc human breast cancer cells into the tail vein. Bioluminescence imaging was used to evaluate metastasis progression. Uptake of (18)F-Z(HER2)(:342)-Affibody and (18)F-FDG was confirmed by coregistration of the PET images with MR and CT images. At the end of the study, the presence of neoplastic cells and HER2 expression in lung tissues, and distribution of the tracer, were assessed ex vivo by immunohistochemistry and autoradiography.
RESULTS: (18)F-Z(HER2)(:342)-Affibody successfully targeted HER2-positive lesions in the lung and allowed detection of metastases as early as 9 wk after injection of cells. In contrast, (18)F-FDG uptake was often masked by surrounding inflammatory changes and was nonspecific for HER2 expression. HER2 expression at a cellular level correlated well with tracer uptake on autoradiography.
CONCLUSION: (18)F-Z(HER2)(:342)-Affibody is a promising tracer for evaluation of HER2 status of breast cancer metastases and is more specific for detecting HER2-positive lesions than (18)F-FDG.
Abstract sourceThis 2012 murine-model study compared HER2-targeted ¹⁸F-ZHER2:342-Affibody PET with ¹⁸F-FDG PET for imaging HER2-positive pulmonary metastases. The authors reported that inflammation could obscure lesions on ¹⁸F-FDG imaging; the findings are from an experimental animal model.
Summary
The study compared PET imaging with the HER2-specific radiotracer ¹⁸F-ZHER2:342-Affibody and ¹⁸F-FDG in a mouse model of breast cancer lung metastases. The authors reported that the Affibody tracer targeted HER2-positive lung lesions, while surrounding inflammation could mask lesions on ¹⁸F-FDG images. This was an experimental animal study; its findings do not establish clinical performance in people. See the publisher’s article and PubMed record.
Cite this work
Gabriela Kramer-Marek, Marcelino Bernardo, Dale O. Kiesewetter, Ulas Bagci, Monika Kuban, Aras Omer, Rafal Zielinski, Jurgen Seidel, Peter Choyke, Jacek Capala (2012). PET of HER2-positive pulmonary metastases with ¹⁸f-ZHER2:342 affibody in a murine model of breast cancer: comparison with ¹⁸f-FDG. Journal of Nuclear Medicine, 53(6), 939–946 https://doi.org/10.2967/jnumed.111.100354
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